LabCorp to deny physicians access to western blot tests for Lyme disease

Labcorp will not offer a western blot test for individuals unless they are positive or equivocal for the Enzyme Immunoassay (EIA) or Immunoflorescense (IFA) screening tests for Lyme disease as of August 11, 2014.[1]

img-ldpr2Physicians have been disappointed by the poor sensitivity of the EIA or IFA screening tests for Lyme disease. The sensitivity of the whole-cell enzyme-linked immunosorbent assay (ELISA) to the B31 strain typically falls between 33-49% for patients presenting with an EM.[2-4] The sensitivity of the Food and Drug Administration (FDA) approved complement peptide C6 (C6-peptide) was 37% in 89 clinically well-defined individuals with LD [5] and 66.5% 403 sera from patients with an EM rash.[6]

Physicians have commonly ordered the western blot test for Lyme disease even in the absence of positive or equivocal testing. An IgM Western blot test can persist for at least 2 years in individuals with established Lyme disease infection. A IgM WB can persist for months to years in LD even if an individual is treated with antibiotics.[7-9]  An IgG can be positive in individuals with a negative screening test.

LabCorp’s decision to deny physician assess to western blot test for Lyme disease only makes testing sensitive than it already is.

It important that LabCorp reverse their position and allow physicians to continue to order western blot tests for Lyme disease even if the EIA and/or IFA are negative. Until then, clinicians may have to direct their patients to other labs.

  1. LabCorp newsletter for clients. Lyme disease testing now employs a two-tier antibody standard, Available from https://  Last accessed 8/16/14.
  2. Aguero-Rosenfeld ME, Nowakowski J, Bittker S, Cooper D, Nadelman RB, Wormser GP. Evolution of the serologic response to Borrelia burgdorferi in treated patients with culture-confirmed erythema migrans. J Clin Microbiol, 34(1), 1-9 (1996).
  3. Trevejo RT, Krause PJ, Sikand VK et al. Evaluation of two-test serodiagnostic method for early Lyme disease in clinical practice. J Infect Dis, 179(4), 931-938 (1999).
  4. Aguero-Rosenfeld ME, Nowakowski J, McKenna DF, Carbonaro CA, Wormser GP. Serodiagnosis in early Lyme disease. J Clin Microbiol, 31(12), 3090-3095 (1993).
  5. Ang CW, Notermans DW, Hommes M, Simoons-Smit AM, Herremans T. Large differences between test strategies for the detection of anti-Borrelia antibodies are revealed by comparing eight ELISAs and five immunoblots. Eur J Clin Microbiol Infect Dis,  (2011).
  6. Wormser GP, Schriefer M, Aguero-Rosenfeld ME et al. Single-tier testing with the C6 peptide ELISA kit compared with two-tier testing for Lyme disease. Diagn Microbiol Infect Dis,  (2012).
  7. Steere AC, Hardin JA, Ruddy S, Mummaw JG, Malawista SE. Lyme arthritis: correlation of serum and cryoglobulin IgM with activity, and serum IgG with remission. Arthritis Rheum, 22(5), 471-483 (1979).
  8. Massarotti EM, Luger SW, Rahn DW et al. Treatment of early Lyme disease. Am J Med, 92(4), 396-403 (1992).
  9. Craft JE, Grodzicki RL, Shrestha M, Fischer DK, Garcia-Blanco M, Steere AC. The antibody response in Lyme disease. Yale J Biol Med, 57(4), 561-565 (1984).

25 Replies to "LabCorp to deny physicians access to western blot tests for Lyme disease"

  • KarlaL
    08/21/2014 (1:57 am)

    I called LabCorp last week and I was told that physicians can still order a stand alone Western blot. What physicians can no longer order is a stand-alone EIA test. If the EIA is positive, then a Western blot will automatically be run, which was not the case before. If the EIA is negative, a Western blot will not be run, but a physician can still order it separately. So my question is, “are different people being told different things about what this new policy means?” Several patients in my online support groups have said that even before this policy was in place, that they were denied Western blots from LabCorp when their EIAs were negative. I for one would like to see LabCorp make a public statement clarifying their new policy.

    In either case, the CDC’s endorsement of the two-tier serology test is the root of the problem here. Patients from Lyme endemic areas already know how the two-tier serology test has failed so many people. Yet the CDC continues to stand behind their flawed studies and support the test. For one, I move to transfer the CDC Lyme office from their isolated enclave in Boulder CO to a Lyme endemic area like Poughkeepsie NY. Then the CDC officers will see for themselves how unreliable the two-tier serology test is, because they will witness their own children, families, friends, and neighbors falling ill with chronic disabling illness, because so few doctors will treat without a positive test.

  • Paula Shick
    08/20/2014 (11:26 pm)

    Ad nausea

  • NEWS: LabCorp's unwelcome policy change on Lyme
    08/20/2014 (9:06 pm)

    […] Click here for Dr. Dan Cameron’s explanation. […]

  • K.C.
    08/20/2014 (6:00 pm)

    To reach LabCorp Customer Service, Call: 800-762-4344
    Select the option for “Report or result” and then into customer service. They might want a patient number; simply say you are calling as a patient advocate, not as a current patient with a lab you can reference (unless you have one they did this two-tier testing to). Refer to the July 2014 edition of LabHorizons, page 8. Have this saved to your device and offer to email it if they do not have access. Be polite and reasonable. It takes patience and persistence to change policy.

  • K.C.
    08/20/2014 (5:19 pm)

    I called LabCorp to complain about this, and this is MISINFORMATION. The Western Blot is offered as a standalone test. If a doctor orders only the ELISA and it comes back POSITIVE they AUTOMATICALLY RUN THE WESTERN BLOT, instead of waiting on a doctor to requisition it because many doctors fail to follow up with Western Blot. This is an overall IMPROVEMENT in testing… If only the ELISA was ordered, they do not follow with Western Blot if the Elisa is negative. Still a problem, IMO, but their Western Blot is also not sensitive enough, IMO. If doctor orders ELISA AND Western Blot, they run BOTH regardless of the ELISA being pos or neg. I was told that this is the company policy by the customer service person in their lab department who has run these tests herself. If you have had an experience that differs from what I was told was company policy, CALL THEM and complain but have your case number ready and a copy of your lab in hand!

    • K.C.
      08/20/2014 (5:37 pm)

      I just read the literature myself…because if I was given wrong information, I am convinced that the lady I talked to was herself misinformed as she was very polite, very understanding of my concern to the point of agreeing with my stance, and logical. This could be a LabCorp CYA public maneuver even though it will certainly cause less people to be properly diagnosed. But regardless I just sent this info to my dad who works in Information Systems at LabCorp and has access and working relationship with people who might be able to do something.

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